The present invention pertains to the room temperature crosslinking of unsaturated polyester resins and more particularly, to accelerating the room temperature crosslinking of such polyester resins with an organosulfur compound and metal salts.
Organosulfur compounds and metal salts are known in the prior art for accelerating (also called promoting) the room temperature crosslinking of unsaturated polyester resins in the presence of an organic peroxide. U.S. Pat. No. 2,946,770 discloses the use of an organic sulphonium compound in combination with a quaternary ammonium compound and a copper or iron salt to accelerate the polymerization time. U.S. Pat. No. 3,333,021 teaches the use of mercaptans in combination with vanadium salts as an accelerator system. British Pat. No. 1,170,983 discloses the use of a 2-mercapto-alcohol in combination with a cobalt or vanadium salt as an accelerator. None of these patents teaches the present invention.